1. Field of the Invention
The present invention relates to the cooling of turbine rotors, especially gas turbines, and, more particularly, to airplane turboreactors.
2. Description of the Prior Art
The need has long been acknowledged to cool the mobile blades of gas turbines, especially of airplane turboreactors, and, in this regard, it is known that a cooling fluid, in most cases air, is circulated through tubes which cross the blades radially. However, the present technological trend is to always increase the rotation velocity of the turbines and the temperature of the hot gases which propel them. Thus, the rotor discs which carry the blades of modern turbines are subjected to high outward-flow pull and elevated temperatures which reduce their mechanical resistance. Therefore, research has also focussed on cooling the turbine discs which, as a result of their heavy load, include a very thick ring-shaped base and a disc which thins out gradually to the rim which supports the blades. It is already known (French patent application No. 2,292,866, published) that, in this regard, the cooling fluid can be circulated through channels in the turbine disc which supports these blades. With respect to familiar modes of implementation, these channels are bored in the disc gradually, or their center lines are located in its cross plane of symmetry.